using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Mail;
using System.Net;
using System.Collections;
using OpenPop.Pop3;
using OpenPop.Mime;
using System.Net.Sockets;
using OpenPop.Pop3.Exceptions;
using System.ComponentModel;
using System.Threading;

namespace SafeMobileLib
{
    public class EmailServerSSL
    {

        private Pop3Client popClient;
        private string serverIP;
        private int port;
        private string loginName;
        private string password;
        private bool isSSL = true;
        private Int64 lastEmailTime = 0;
        private Int64 startEmailServiceTime = 0;
        public static Dictionary<string, int> blackList = new Dictionary<string, int>();
        public const int MAX_ATTEMPTS = 100;

        // blank constructor in order to be used in Email Checking
        public EmailServerSSL()
        {
        }

        //constructor
        public EmailServerSSL(string _serverIP, string _port, string _logName, string _pass)
        {
            bool result = Int32.TryParse(_port, out port);
            if (!result)
            {
                Console.WriteLine("Email port not numeric, error in EmailServerSSL constructor.");
                return;
            }

            serverIP = _serverIP;
            loginName = _logName;
            password = _pass;

            popClient = new Pop3Client();

            // create the pop connection
            ConnectEmailPopServer();

        }


        public EmailServerSSL(string _serverIP, Int32 _port, string _logName, string _pass, bool _isSSL)
        {
            serverIP = _serverIP;
            loginName = _logName;
            port = _port;
            password = _pass;
            isSSL = _isSSL;

            startEmailServiceTime = DateTo70Format(DateTime.UtcNow);

            // create the pop connection
            ConnectEmailPopServer();

        }
        #region popCLient events
        private void AddEvent(string strEvent)
        {
        }

        private void popClient_CommunicationBegan(object sender, EventArgs e)
        {
            AddEvent("CommunicationBegan");
        }

        private void popClient_CommunicationOccured(object sender, EventArgs e)
        {
            AddEvent("CommunicationOccured");
        }

        private void popClient_AuthenticationBegan(object sender, EventArgs e)
        {
            AddEvent("AuthenticationBegan");
        }

        private void popClient_AuthenticationFinished(object sender, EventArgs e)
        {
            AddEvent("AuthenticationFinished");
        }

        private void popClient_MessageTransferBegan(object sender, EventArgs e)
        {
            AddEvent("MessageTransferBegan");
        }

        private void popClient_MessageTransferFinished(object sender, EventArgs e)
        {
            AddEvent("MessageTransferFinished");
        }

        private void popClient_CommunicationLost(object sender, EventArgs e)
        {
            AddEvent("CommunicationLost");
        }


        #endregion

        /// <summary>
        /// Set the time of the last email as written in the DataBase. 
        /// Only newer emails will be handled
        /// </summary>
        /// <param name="time">Unix TimeStap for the last email time</param>
        public void setLastEmailTime(Int64 time)
        {
            lastEmailTime = time;
        }

        /// <summary>
        /// Get the latest email time as received from the server
        /// </summary>
        /// <returns>Unix timestamp of the latest email</returns>
        public Int64 getLastEmailTime()
        {
            return lastEmailTime;
        }

        /// <summary>
        /// Get the emails from the server and check which ones were not 
        /// parsed 
        /// </summary>
        /// <returns>A list of emails</returns>
        public ArrayList getEmails()
        {
            ArrayList ret = new ArrayList();
            try
            {
                if (popClient != null && !popClient.Connected)
                {
                    
                    Console.ForegroundColor = ConsoleColor.Yellow;
                    Console.WriteLine("PopServer is not authenticated/connected. Check the email address, password and settings");
                    Console.ForegroundColor = ConsoleColor.Gray;

                    // reconnect if the email server is outlook one 
                    if (serverIP.Contains("outlook"))
                        ConnectEmailPopServer();
                }
                else
                {
                    // reconnect if the email server is not the outlook one 
                    if (!serverIP.Contains("outlook"))
                        ConnectEmailPopServer();
                    else
                    {
                        // reconnect every 10 minutes
                        if (((DateTo70Format(DateTime.UtcNow) - startEmailServiceTime) / 60) % 10 == 0)
                        {
                            Console.ForegroundColor = ConsoleColor.Yellow;
                            Console.WriteLine("RECONNECTING");
                            Console.ForegroundColor = ConsoleColor.Gray;
                            ConnectEmailPopServer();
                        }
                    }

                    int messageCount = 0;

                    try
                    {
                        messageCount = popClient.GetMessageCount();
                       
                    }
                    catch (InvalidUseException iue) {}

                    catch (Exception ex)
                    {
                        Console.ForegroundColor = ConsoleColor.Red;
                        Console.WriteLine("Socket Exception -> " + ex.ToString());
                        Console.ForegroundColor = ConsoleColor.Gray;

                        popClient = null;
                    }

                    // save the latest time before this search
                    Int64 initialLatestTime = lastEmailTime;
                    
                    int newEmails = 0;


                    // Messages are numbered in the interval: [1, messageCount]
                    // Ergo: message numbers are 1-based.
                    // Most servers give the latest message the highest number
                    List<OpenPop.Mime.Message> messageList = new List<OpenPop.Mime.Message>();

                    for (int i = messageCount; i > 0; i--)
                    {
                        
                        //try
                        //{
                            OpenPop.Mime.Message  email = popClient.GetMessage(i);
                            messageList.Add(email);
                        //}
                        //catch (Exception ex)
                        //{
                            
                        //    Console.ForegroundColor = ConsoleColor.Cyan;
                        //    Console.WriteLine("Exception [Marked deletion?]-> " + ex.ToString());
                        //    Console.ForegroundColor = ConsoleColor.Gray;
                        //}
                    }

                    for (int i=0; i < messageCount; i++)
                    {
                        OpenPop.Mime.Message email = messageList[i];

                        if (email != null)
                        {

                            // check if the message was already parsed by verifying email time with initialLatestTime
                            // and close the parsing
                            if (initialLatestTime >= DateTo70Format(email.Headers.DateSent.ToUniversalTime()))
                            {
                                break;
                            }

                            // save the latest time to the first one (assuming it's the newest)
                            if (i == messageCount)
                            {
                                this.lastEmailTime = DateTo70Format(email.Headers.DateSent.ToUniversalTime());
                            }

                            // this email is new
                            newEmails++;

                            Console.WriteLine("-----------------------------------------------------------------");
                            Console.WriteLine("From: " + email.Headers.From);

                            if (email.Headers.To.Count() >= 0)
                                Console.WriteLine("To: " + email.Headers.To[0]);

                            Console.WriteLine("Subject: " + email.Headers.Subject);

                            Console.WriteLine("Date: " + email.Headers.DateSent.ToUniversalTime().ToShortTimeString()
                                        + "[" + DateTo70Format(email.Headers.DateSent.ToUniversalTime()) + "]");

                            
                            MessagePart html = email.FindFirstHtmlVersion();
                            if (html != null)
                            {
                                string text = RemoveHTMLtags(html.GetBodyAsText());
                                Console.WriteLine("Text: " + text.Substring(0, (text.Length > 30 ? 30 : text.Length)) + (text.Length > 30 ? "..." : ""));
                            }
                            else
                                html = email.FindFirstPlainTextVersion();

                            EmailtoSMS ets = processMessage(email.Headers.Subject, RemoveHTMLtags(html.GetBodyAsText()), email.Headers.From.ToString());
                            if ((ets.id != "") && (ets.text == ""))
                            {
                                Console.WriteLine("Incorrect email body " + RemoveHTMLtags(html.GetBodyAsText()));
                            }
                            else if ((ets.id != "") && (ets.text != ""))
                            {
                                ret.Add(ets);
                            }

                            
                        }
                        else
                        {
                            Console.WriteLine("-----------------------------------------------------------------");
                            Console.WriteLine("BAD email");
                        }

                    }

                    Console.WriteLine("Got " + newEmails + " new emails [total " + messageCount +"] " );
                }

            }
            catch (Exception ex)
            {
                Console.WriteLine("getEmails() from EmailServerSSL Exception: " + ex.Message + ex.ToString());
            }
            return ret;
        }

        public ArrayList getEmailsRaw()
        {
            ArrayList ret = new ArrayList();
            try
            {
                Console.ForegroundColor = ConsoleColor.Cyan;
                Console.WriteLine(String.Format("Ser = {0}    Psw = {1}   SSL = {2}", serverIP, password, isSSL));
                Console.ForegroundColor = ConsoleColor.Gray;

                
                int messageCount = popClient.GetMessageCount();
                Console.WriteLine("Got " + messageCount + " emails");

                // Messages are numbered in the interval: [1, messageCount]
                // Ergo: message numbers are 1-based.
                // Most servers give the latest message the highest number

                List<OpenPop.Mime.Message> messageList = new List<OpenPop.Mime.Message>();
                for (int i = messageCount; i > 0; i--)
                {
                    OpenPop.Mime.Message email = popClient.GetMessage(i);
                    messageList.Add(email);
                }


                for (int i = 0; i< messageCount; i++)
                {
                    OpenPop.Mime.Message email = messageList[i];

                    if (email != null)
                    {
                        Console.WriteLine("-----------------------------------------------------------------");
                        Console.WriteLine("From: " + email.Headers.From);
                        if (email.Headers.To.Count >= 0)
                            Console.WriteLine("To: " + email.Headers.To[0]);
                        Console.WriteLine("Subject: " + email.Headers.Subject);

                        string body = RemoveHTMLtags(email.MessagePart.Body.ToString());

                        EmailtoSMS ets = new EmailtoSMS();
                        ets.from = email.Headers.From.ToString();
                        ets.text = body;
                        ets.id = "";

                        if (ets.from.Contains("@"))
                        {
                            string temp = (ets.from.Split("@".ToCharArray()))[0];

                            int i_id = 0;
                            bool valid = Int32.TryParse(temp, out i_id);

                            if (valid)
                                ets.id = i_id.ToString();

                        }

                        if ((ets.id != "") && (ets.text == ""))
                        {
                            Console.WriteLine("Incorrect email body " + email.MessagePart.Body.ToString());
                        }
                        else if (ets.text != "")
                        {
                            try
                            {
                                popClient.DeleteMessage(i);
                            }
                            catch (Exception e)
                            {
                                Console.ForegroundColor = ConsoleColor.Cyan;
                                Console.WriteLine("Exception [Marked deletion?]-> " + e.ToString());
                                Console.ForegroundColor = ConsoleColor.Gray;
                            }
                            ret.Add(ets);
                        }
                    }
                    else
                    {
                        Console.WriteLine("-----------------------------------------------------------------");
                        Console.WriteLine("BAD email");
                    }
                }
                
            }
            catch (Exception ex)
            {
                Console.WriteLine("getEmails() from EmailServerSSL Exception: " + ex.Message + ex.ToString());
            }
            return ret;
        }


        public static void HandleBlacklist(string key)
        {
            // add key to backlist 
            if (!blackList.ContainsKey(key))
                blackList.Add(key, MAX_ATTEMPTS);
        }

        public static bool IsBlacklisted(string key)
        {

            if (!blackList.ContainsKey(key))
                return false;

            // avoid to connect to pop3 MAX_ATTEMPTS times => give another chance to try to connect to pop 3 when count = 0
            int count = blackList[key];
            if (count == 0)
            {
                blackList.Remove(key);
                return false;
            }

            blackList[key] = count - 1;
            return true;
        }


        /// <summary>
        /// Connect to the Pop Server in order to be used to get the emails
        /// </summary>
        private void ConnectEmailPopServer()
        {
            if (IsBlacklisted(serverIP))
            {

                Utils.WriteLine($"ConnectEmailPopServer : Could not conenct to the pop server '{serverIP}'. The pop server '{serverIP}' is in blacklist count = {blackList[serverIP]}");
                return;
            }


            Thread t = new Thread(() =>
            {
                ConnectAsync();
            });

            t.Start();
        }

        private void ConnectAsync()
        {
            try
            {

                if (popClient != null && popClient.Connected)
                    popClient.Disconnect();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());

            }

            popClient = null;
            popClient = new Pop3Client();

            try
            {
                // Connect to the server
                popClient.Connect(serverIP, port, isSSL);

                // Authenticate ourselves towards the server
                popClient.Authenticate(loginName, password);
            }
            catch (PopServerNotFoundException ee)
            {
                Console.ForegroundColor = ConsoleColor.Yellow;
                Console.WriteLine("PopServerNotFoundException -> " + ee.ToString());
                Console.ForegroundColor = ConsoleColor.Gray;

                HandleBlacklist(serverIP);

            }
            catch (InvalidLoginException e)
            {
                Console.ForegroundColor = ConsoleColor.Yellow;
                Console.WriteLine("InvalidLoginException -> " + e.ToString());
                Console.ForegroundColor = ConsoleColor.Gray;

                HandleBlacklist(serverIP);
            }
            catch (Exception ex)
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("ConnectEmailPopServer -> " + ex.ToString());
                Console.ForegroundColor = ConsoleColor.Gray;

                HandleBlacklist(serverIP);
            }
        }


        private EmailtoSMS processMessage(string subj, string body, string from)
        {
            EmailtoSMS obj = new EmailtoSMS();
            obj.from = from;
            String s = subj.ToUpper();

            if (s.Contains("GROUPID[") && subj.Contains("]"))
            {
                obj.id = s;
                obj.id = obj.id.Remove(0, s.IndexOf("GROUPID[") + 8);
                obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                obj.is_group = true;
            }
            else if (s.Contains("GRPID[") && subj.Contains("]"))
            {
                obj.id = s;
                obj.id = obj.id.Remove(0, s.IndexOf("GRPID[") + 6);
                obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                obj.is_group = true;
            }
            else if (s.Contains("ID[") && subj.Contains("]"))
            {
                obj.id = s;
                obj.id = obj.id.Remove(0, s.IndexOf("ID[") + 3);
                obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                obj.is_group = false;
            }

            if (obj.id.Length > 0)
            { // ID prezent in subject
                s = body.ToUpper();
                if (s.Contains("BODY[") && body.Contains("]"))
                {
                    obj.text = body;
                    obj.text = obj.text.Remove(0, s.IndexOf("BODY[") + 5);
                    obj.text = obj.text.Remove(obj.text.IndexOf("]"));
                    if (obj.text.Length > 139)
                        obj.text = obj.text.Remove(140);
                }
            }
            else
            {  //check for id in email body
                s = body.ToUpper();
                if (s.Contains("GROUPID[") && s.Contains("]"))
                {
                    obj.id = s;
                    obj.id = obj.id.Remove(0, s.IndexOf("GROUPID[") + 8);
                    obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                    obj.is_group = true;
                }
                else if (s.Contains("GRPID[") && s.Contains("]"))
                {
                    obj.id = s;
                    obj.id = obj.id.Remove(0, s.IndexOf("GRPID[") + 6);
                    obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                    obj.is_group = true;
                }
                else if (s.Contains("ID[") && s.Contains("]"))
                {
                    obj.id = s;
                    obj.id = obj.id.Remove(0, s.IndexOf("ID[") + 3);
                    obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                    obj.is_group = false;
                }
                else if (s.Contains("RPL[") && s.Contains("]"))
                {
                    obj.id = s;
                    obj.id = obj.id.Remove(0, obj.id.IndexOf("RPL[") + 4);
                    obj.id = obj.id.Remove(obj.id.IndexOf("]"));
                    obj.text = obj.id;
                    obj.is_group = true;
                    obj.is_sierra = true;
                     if (obj.from.Contains("<") && obj.from.Contains(">"))
                     {
                         obj.from = obj.from.Remove(0, obj.from.IndexOf("<") + 1);
                         obj.from = obj.from.Remove(obj.from.IndexOf(">"));
                     }
                }

                if (obj.id.Length > 0)
                {
                    s = body.ToUpper();
                    if (s.Contains("BODY[") && s.Contains("]"))
                    {
                        obj.text = body;
                        obj.text = obj.text.Remove(0, s.IndexOf("BODY[") + 5);
                        obj.text = obj.text.Remove(obj.text.IndexOf("]"));
                        if (obj.text.Length > 139)
                            obj.text = obj.text.Remove(140);
                    }
                }

            }

            Console.WriteLine("ID: " + obj.id);
            Console.WriteLine("Text: " + obj.text);
            Console.WriteLine("-----------------------------------------------------------------");
            return obj;
        }

        public static void sendEmail(string server, Int32 _port, string user, string pass, MailMessage mailMessage, Boolean enableSSL)
        {
            SmtpClient mailClient = new SmtpClient();
            mailClient.Host = server;
            mailClient.Port = _port;
            NetworkCredential cred = new NetworkCredential(user, pass);
            mailClient.Credentials = cred;
            mailClient.EnableSsl = enableSSL;
            mailClient.Send(mailMessage);
            Console.WriteLine("------Sending email on " + server + " TO: " + mailMessage.To[0].ToString() + "--------------");
        }

        public void sendEmailWithFeedback(string server, Int32 _port, string user, string pass, MailMessage mailMessage, Boolean enableSSL)
        {
            Console.WriteLine("------Sending email on " + server + " TO: " + mailMessage.To[0].ToString() + "--------------");
            try
            {
                SmtpClient mailClient = new SmtpClient();
                mailClient.Host = server;
                mailClient.Port = _port;
                NetworkCredential cred = new NetworkCredential(user, pass);
                mailClient.Credentials = cred;
                mailClient.EnableSsl = enableSSL;
                mailClient.Send(mailMessage);
                if (OnMailSendComplete != null)
                    OnMailSendComplete(true);
            }
            catch
            {
                if (OnMailSendComplete != null)
                    OnMailSendComplete(false);
            }
            
        }

        public static void sendListofEmail(string server, Int32 _port, string user, string pass, ArrayList ListofmailMessage, Boolean enableSSL)
        {
            SmtpClient mailClient = new SmtpClient();
            mailClient.Host = server;
            mailClient.Port = _port;
            mailClient.UseDefaultCredentials = false;
            NetworkCredential cred = new NetworkCredential(user, pass);
            mailClient.Credentials = cred;
            mailClient.EnableSsl = enableSSL;
            foreach (MailMessage obj in ListofmailMessage)
            {
                obj.IsBodyHtml = true;
                mailClient.Send(obj);
                Console.WriteLine("------Sending email on " + server + " TO: " + obj.To[0].ToString() + "--------------");
            }
        }

        public string RemoveHTMLtags(string _data)
        {
            string data = _data;

            while(data.Contains('<'))
            {
                int firstindex = data.IndexOf('<');
                int secondindex = data.IndexOf('>');

                data = data.Remove(firstindex, secondindex - firstindex+1);
            }
            data = data.Replace("\n","");
            data = data.Replace("\r", "");

            return data;
        }


        /// <summary>
        /// Check the configuration of the POP Server to see if it's valid. The check consists in reading the email
        /// list from the account provided
        /// </summary>
        /// <param name="_serverIP">POP Server name or IP</param>
        /// <param name="_port">POP Server Port</param>
        /// <param name="_logName">Email address from which the emails will be read</param>
        /// <param name="_pass">Email Account password used to read the email</param>
        /// <param name="_isSSL">Flag if the POP connection is SSL encrypted or not</param>
        public void CheckPopServerSettings(string _serverIP, Int32 _port, string _logName, string _pass, bool _isSSL)
        {
            bool result = false;
            string message = "";

            Pop3Client tmpClient = new Pop3Client();

            try
            {
                // Connect to the server
                tmpClient.Connect(_serverIP, _port, _isSSL);

                // Authenticate ourselves towards the server
                tmpClient.Authenticate(_logName, _pass);

                // Get the message count to check if the email settings are correct
                int messageCount = tmpClient.GetMessageCount();
                
                message = "Success";
                result = true;
            }
            catch (PopServerNotFoundException ee)
            {
                message = "PopServerNotFoundException";
            }
            catch (InvalidLoginException e)
            {
                message = "InvalidLoginException";
            }
            catch (Exception ex)
            {
                message = "InvalidLoginException";
            }


            // trigger response
            if(OnPopServerCheckResponseReceived != null)
                OnPopServerCheckResponseReceived(result, message);
        }


        /// <summary>
        /// Check the configuration of the SMTP Server to see if it's valid. The check consists in sending a simple 
        /// text mail message to the emailAddress provided by the user
        /// </summary>
        /// <param name="_serverIP">SMTP Server name or IP</param>
        /// <param name="_port">SMTP Server Port</param>
        /// <param name="_logName">Email address from which and to which the email will be send</param>
        /// <param name="_pass">Email Account password used to send the email</param>
        /// <param name="_isSSL">Flag if the SMTP connection is SSL encrypted or not</param>
        public void CheckSmtpServerSettings(string _serverIP, Int32 _port, string _logName, string _pass, bool _isSSL)
        {
            bool result = false;
            string responseMessage = "";

            try
            {
                MailAddress from = new MailAddress(_logName);
                MailAddress to = new MailAddress(_logName);
                MailMessage message = new MailMessage(from, to);
                message.IsBodyHtml = true; // This line
                string tab = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
                message.Subject = "Email test from Dispatch System";
                message.Body = "Hi.<br/>You have tested your email server settings from the Dispatch System. <br/>"  +
                                "Your valid configuration is:  <b><br/><br/>" +
                                tab + _serverIP + ":" + _port + "  <br/>" +
                                tab + "This server " + (_isSSL ? "requires" : "do not requires") + " SSL encryption.  </b><br/><br/>" +
                                "Thank you!";

                SmtpClient mailClient = new SmtpClient();
                mailClient.Host = _serverIP;
                mailClient.Port = _port;
                NetworkCredential cred = new NetworkCredential(_logName, _pass);
                mailClient.Credentials = cred;
                mailClient.EnableSsl = _isSSL;
                mailClient.Send(message);

                result = true;
                responseMessage = "Success";
            }
            catch (Exception ex)
            {
                result = false;
                responseMessage = "Exception " + ex.ToString();
            }

            // trigger event
            if(OnSmtpServerCheckResponseReceived != null)
                OnSmtpServerCheckResponseReceived(result, responseMessage);

        }

        /// <summary>
        /// Get the unix timestamp of a specific Date
        /// </summary>
        /// <param name="param">Date which needs to be converted</param>
        /// <returns>An int representing the number of seconds since 1 Jan 1970</returns>
        private uint DateTo70Format(DateTime param)
        {
            long nOfSeconds;
            //Console.WriteLine("DateTo70Format param=" + param);
            System.DateTime dt70 = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
            TimeSpan span = param - dt70;
            nOfSeconds = (long)span.TotalSeconds;
            return ((uint)nOfSeconds);
        }

        #region EVENTS
        public delegate void PopServerCheckDEl(bool isValid, string responseMessage);
        public event PopServerCheckDEl OnPopServerCheckResponseReceived;

        public delegate void SmtpServerCheckDEl(bool isValid, string responseMessage);
        public event SmtpServerCheckDEl OnSmtpServerCheckResponseReceived;

        public delegate void MailSendComplete(bool result);
        public event MailSendComplete OnMailSendComplete;

        #endregion

    }

    public class EmailtoSMS
    {
        public String from;
        public String id;
        public String text;
        public Boolean is_group;
        public Boolean is_sierra;

        public EmailtoSMS()
        {
            from = "";
            id = "";
            text = "";
            is_group = false;
            is_sierra = false;
        }
    }

}